If I put my foot exposed to the ground and put my finger to the USB power, will I be electrocuted? Do the electrons from the USB power pass over my hand, run to my foot, and go to the ground? I think the ground must be an object that can pull excess electrons towards it, and the pulled electrons will spread out to the ground or go to somewhere that is more positive, so that the reaction can continue forever. If I put an LED light with one terminal to power and one terminal going to the ground, it will emit continuously. With this argument, I think the ground or wall must be conductive. But ironically, the truth is not as I expected. Can someone please explain to me what happens inside these reactions?